Nail feed mechanism



June E3, 1967 C. A. DAVIS 3,325,051

NAIL FEED MECHANISM I Filed Feb. 9, 1966 E37-*dg www ullt/iE/VTOR Ui www United States Patent O 3,325,051 NAIL FEED MECHANISM Charles A. Davis, Saugus, Mass., assigner to W. J. `Young Machinery Co., Inc., Peabody, Mass., a corporation of Massachusetts Filed Feb. 9, 1966, Ser. No. 526,269 6 Claims. (Cl. 221-93) The present invention relates to an improved nail feed mechanism of the type shown in and for use with apparatus described in United States Letters Patents 3,071,291 and 3,142,841.

In automatic nailing machines, and in particular in nailing machines designed for use in the shoe industry, it is desirable to provide a means for feeding several nails simultaneously to the nailing machines. Such devices have particular utility for simultaneously driving four or more nails through a heel or comparable element into other shoe elements. Heretofore, mechanism of the type described in the aforo-mentioned patents utilizes a plurality of chutes each of which conveys a column of nail heads upwardly from a rocking hopper to a transport which in turn moves these nails to the nailing mechanism. The means which have been previously used for controlling the feed of the nails so that nails may be fed individually from each chute to the transport, ordinarily comprise a rack member provided with a pawl for each chute. These pawls each engage a column of nails and, upon actuation of the rack, permit delivery of an individual nail from the column in each chute to the transport mechanism, whereby the transport mechanism may simultaneously carry one nail from each chute to the nailing mechanism.

One of the principal problems encountered in controlling the delivery of individual nails from a column in each chute is the problem of providing adequate means for separating the lowermost nail in the column of nails for delivery from the chute. Mechanisms which have been utilized heretofore make no provisions for handling nails of different sizes or nails having dilferent sized heads. Consequently, existing machines have been limited in utility and adaptability. In these machines if one desires to utilize nails of dilferent sizes, substantial modification or substitution of the means for separating nails has been necessary.

It is therefore an object of the present invention to provide an improved nailing machine feed mechanism which may be easily adjusted to handle nails of diilerent sizes or nails having different sized hea-ds. It is also an object of this invention to provide an improved nailing machine feed mechanism which is relatively inexpensive to manufacture, adjust and maintain. A further object of this present invention is to provide a feed mechanism for nailing machines which is adapted to operate with a high degree of eiciency and with a speed limited only to the nailing speed of the machine.

It is a still further object of the present invention to provide an improved pawl and rack arrangement designed lto separate the lowermost nail in each of several columns of nails from the columns themselves with ease and eiiciency.

These and other objects and advantages of the present invention will be more clearly understood from a consideration of the accompanying drawings in which:

FIG. 1 is a top plan view of the invention as used in conjunction with a nailing machine of the type illustrated in the aforesaid patents and with duplicate portions indicated by dotted extension;

FIG. 2 is a cross-sectional view taken along the line 2 2 of FIG. 1; and

FIG, 3 is a cross-sectional view taken along the line 3-3 of FIG. 1.

3,325,051 Patented June 13, 1967 lCe Referring to the drawings, there is illustrated a plurality of chutes 1. These chutes are positioned parallel to one another and may comprise any reasonable number with four being shown for illustrative purposes. These chutes are normally positioned in a nailing machine at an inclined angle as, for example, 45 degrees. Theupper end of the chute is operatively connected to a hopper through a gate mechanism while the lower end of the chutes are operatively connected to a nail-transfer mechanism in the same fashion as the chutes illustrated at 11 in United States Letters Patent 3,071,291 and 3,142,841. Except as herein described, the portions associated with the chutes not shown in the accompanying drawings, may be the same as those portions shown in the aforementioned patents.

Each chute 1 may comprise two halves 2 and 3, positioned parallel to one another and spaced apart by a slot 4 adapted to receive the body of a nail. The upper surfaces of these walls 2 and 3 are adapted to support the heads 5 of a column of nails 6 while the bodies 7 of the nails extend in parallel fashion into the slot 4 between the walls 2 and 3. Each chute 1 is provided with a stepped or shoulder section 8 so that the lower part of the upper surfaces of the walls 2 and 3 are offset from the upper portion of the upper surfaces of the walls 2 land 3, as illustrated at 9. y A mechanism for controlling the feed o-f the nails which are supported in the chutes extends transversely across these parallel chutes. This mechanism 10 includes -a rack 11. The rack 11 comprises an elongated member which extends longitudinally across the chutes. This rack is provided with ends 12 and 13 having a solid Ilthickness from the front or upper wall 14 to the rear or back wall 15 of the rack. A center section 16 is recessed so that the rack is thinner in this center section than at its outer ends 12 and 13. The rack 11 is supported at its ends 12 and 13 respectively, by brackets 18 `and 19, so that the lower surface 15 of the rack lies parallel to the upper surfaces of the walls 2 and 3, with the upper edge 22 of the rack 11 extending parallel to and in alignment with the shoulders 8 of each of the chutes. The frames 18 and 19 are designed to permit longitudinal movement of therack and its associated mechanism so that the rack may be moved on its longitudinal axis across the chutes 1. These frames may, therefore, comprise a base member 24 secured to the nailing machine feed mechanism and having a recess within which is positioned the rack member 11. A retaining plate or bracket 25 extends across the frames and is secured to it by a plurality of screws 26 or other suitable means whereby the rack and its associated mechanism is retained within a transversely extending recess in the base member 24.

The upper edge 22 of the rack 11 comprises a first portion which is adapted to engage the lowermost nail 28 of the column of nails in each chute. The rack is also provided with a recess 29 in the upper edge 22 for each column of nails or chute 1. These recesses 29 comprise a second portion of the rack that is adapted to be aligned with the column of nails upon longitudinal movement of the rack 11. The recesses 29 are cut to sufficient depth from the upper edge 22 so that when the recess becomes aligned with the column of nails, the lowermost nail 28 is free to move downwardly into the recess and over the shoulder portion 8 of the chute and thereby freely slide onto the offset portion 9 of the chute.

The rack 11 is suitably connected to a power source for reciprocal movement along .its longitudinal axis. This connection may comprise a link indicated at 30' which is secured by a pin 31 that extends through a hole in the end 12 of the rack.

A bar 40 is positioned within the center portion 16 of the rack 11. This bar preferably extends the length of the center portion 16 with the ends 41 of the bar 40 preferably slidably engaging the side walls defining the center section 16. The bar preferably has a thickness equal to the depth of the recess forming the center section 16 so that the upper surface 42 of the -bar 40 is coplanar with the upper surface 14 of the rack 11. The bar 40 is provided with slots 44 at either end. These slots extend transversely of the length of the bar. Screws 45 extend through the slots 44 and are threaded into the rack 11. These screws 45 have heads which engage the upper surface 42 of the bar 40 at the sides of the slots 44 so that the screws 45 secure the bar 40 to the rack 11. The Width of the bar 40 is narrower than the width of the rack 11. The bar 40 may be laterally adjusted with respect to the rack 11 by appropriately adjusting the relative location of the screws 45 and the slots 44. Thus, the upper edge 46 of the bar 40 may be adjusted in parallel relation toward and from the upper edge 22 of the rack 11.

A plurality of pawls, generally illustrated at 50, are pivotally secured to the bar 40. Each pawl comprises a body 51 with an extending finger 52 having apointed end'53. The body of the pawl 51 is secured to the bar 40 by a pin 55 which extends through the pawl body 51 into the bar 40 where it is secured. Each pin 55 has a head 58 spaced outwardly from the upper surface of the pawl. Intermediate the head 58 of the pin 55 and the pawl is a helical spring 59 coaxially mounted on the pin 55. One end of the helical spring 59 engages a pin 60 while the other end of the helical spring 59 engages a pin 61. Pin 60 is secured to the pawl 52 while pin 61 is secured to the bar 40 so that the pawl is normally tensioned in a counterclockwise direction as viewed in FIG. l. Pin 61 also acts as a stop to limit rotational movement of the pawl 50.

In the operation of this device, the rack 11 is moved laterally in alignment with its longitudinal axis through the drive mechanism connected to the rack by the link 30. This reciprocates the rack from a first position in which the lowermost nail 28 in the column of nails in each chute is engaged and supported by the upper edge 22 of the rack to a second position in which a recess 29 is aligned with the column of nails. In the `first position, the entire column of nails in each chute is supported by the rack against downward movement. As the rack is moved to the left, as viewed in FIGURE l, for simultaneous feeding of a single nail from each chute downwardly to a nail-'transfer mechanism (not shown), the recesses 29 are brought kinto alignment with each ofthe columns. At the same time, the pointed end 53 of each pawl is moved laterally toward the column of nails. The pointed end of each pawl is positioned to engage the column of nails at a point substantially between the head of the lowermost nail 28 and the head of the next lowermost nail 70. As the rack continues to move to the left, as viewed in FIGURE 1, the pointed end 53 of each pawl forces `its way between the head of the lowermost nail 28 and the next lowermost nail 70. This in turn causes the pawl to support the column of nails except for the lowermost nail 28. Thus, when the recess 29 is brought into alignment with the column, the column is still maintained in the chute. It is maintained in the chute, however, at this time by the pawl rwhile the lowermost nail 28 is forced to move downwardly in the chute as the recess 29 cornes into alignment with it.

From the foregoing description of the operation of this 4 device, it can be seen that the distance between the upper edge 22 of the rack. and the pointed end 53 of the pawl must be substantially equal or perhaps be a little greater than the diameter of the heads of the nails in the chute.

Thus, by providing a bar and rack mechanism with the i adjusting slot 44 and screws 45, the distance between the pointed end 36 of each pawl and the upper edge 22 of the rack 11 may be adjusted to accommodate nails of different sizes. Consequently a simple screw adjustment adapts the feed mechanism to different sized nails.

Having described my invention, I claim:

1. A mechanism for controlling the feed of nails supported heads upward in an aligned column by an upwardly extending chute comprising,

a rack extending longitudinally across said chute and having first portion and second portions adapted to bealternately aligned with said chute, said first portion adapted to engage the lowermost nail .in said column when aligned with said chute and said second portion adapted to permit movement of the lowermost nail, when aligned with said chute,

means supporting said rack for reciprocal movement in a direction longitudinal of its length for alternate positioning of said first and second portions in alignment with said chute,

a pawl assembly having an end adapted to engage said heads on movement of said rack, and

means pivotally supporting said pawl assembly on said rack yincluding elements for adjustably supporting said pawl assembly in a direction normal to the length of said rack whereby said pawl assembly end may be adjusted to engage said column at a point intermediate the heads of the lowermost two nails.

2. A mechanism as set forth in claim 1 wherein said means pivotally supporting said pawl assembly includes a bar extending longitudinally of said rack with said bar supporting said pawl assembly,

means interengaging said bar and rack having elements for laterally adjusting said bar in respect to said rack.

3. A mechanism as set forth in claim 2 wherein said means interengaging said bar and rack includes slot means and a pin extending through said slot means and with said pin secured to one of said rack and bar and said slot means formed in the other of rack and bar.

4. A mechanism as set forth in claim 3 including a plurality of chutes and a plurality of pawl assemblies commonly supported on said bar.

5. A mechanism as set :forth in claim 4 wherein said pawl assemblies each include a spring member engaging said pawl at one end and said bar at the other for tensioning said pawl to a selected position of rotation.

6. A mechanism as set forth in claim 4 wherein said rst portion of said rack comprises an edge thereof and said second portion comprises a recess in said edge.

References. Cited UNITED STATES PATENTS 5/19'10 Campbell 221-251 X 7/-1965 `Garvin 221-268 X 

1. A MECHANISM FOR CONTROLLING THE FEED OF NAILS SUPPORTED HEADS UPWARD IN AN ALIGNED COLUMN BY AN UPWARDLY EXTENDING CHUTE COMPRISING, A RACK EXTENDING LONGITUDINALLY ACROSS SAID CHUTE AND HAVING FIRST PORTION AND SECOND PORTIONS ADAPTED TO BE ALTERNATELY ALIGNED WITH SAID CHUTE, SAID FIRST PORTION ADAPTED TO ENGAGE THE LOWERMOST NAIL IN SAID COLUMN WHEN ALIGNED WITH SAID CHUTE AND SAID SECOND PORTION ADPATED TO PERMIT MOVEMENT OF THE LOWERMOST NAIL, WHEN ALIGNED WITH SAID CHUTE, MEANS SUPPORTING SAID RACK OF RECIPROCAL MOVEMENT IN A DIRECTION LONGITUDINAL OF ITS LENGTH FOR ALTERNATE POSITIONING OF SAID FIRST AND SECOND PORTIONS IN ALIGNMENT WITH SAID CHUTE, A PAWL ASSEMBLY HAVING AN END ADAPTED TO ENGAGE SAID HEADS ON MOVEMENT OF SAID RACK, AND MEANS PIVOTALLY SUPPORTING SAID PAWL ASSEMBLY ON SAID RACK INCLUDING ELEMENTS FOR ADJUSTABLY SUPPORTING SAID PAWL ASSEMBLY IN A DIRECTION NORMAL TO THE LENGTH OF SAID RACK WHEREBY SAID PAWL ASSEMBLY END MAY BE ADJUSTED TO ENGAGE SAID COLUMN AT A POINT INTERMEDIATE THE HEADS OF THE LOWERMOST TWO NAILS. 